I think it's largely about race. It's, in my view, the primary tenet of "Trumpism".They aren't simply racist though. This isn't all about race. Its about democracy and power and conspiracy theories and alternate facts and tyranny etc etc.
Example:
This is a politician adopting "Trumpism" as I see it. A clear appeal to racism to win over the racist white voter. A signal that says "Hey, even though I'm a rich multi-millionaire who committed insider trading based off covid intel that I later denied, I'm actually just like you because I dont like these brown people either"